Process for the preparation of zinc oxid for reduction.



UNITED STATES PATENT oriaoa HERMANN PAPE, OF HAMBURG, GERMANY.

PROCESS FOR THE PREPARATION OF ZINC OXID FOR REDUCTION.

No Drawing.

To all whom it may concern:

Be it known that I, IIERMANN larn, a subject of the'nEmperor of Germany, and resident of Hamburg, Germany, have invented a certain new and useful Improvement in Processes for the Preparation of Zinc Oxid for Reduction, of which the following is a specification.

Zinc oxid whiclris Obtained in the usual manner by precipitatin zinc vapor or fumes in dust chambers of fi tering appliances, is exceedingly loose, and resents relatively small density. In additlon to this it is of a viscous or adhesive character, and owing to this latter property and to its small density it is not well adapted for reduction into zinc, so that in the case of zinc oxid of the kind described great losses generally occur in reducing it. Owing to its nature, zine oxid is also unsuited for transport, as it is hardly possible to convey it owing to its looseness, even when tarpaulins are used for covering thetrucks. It is therefore necessary to pack the oxid into sacks or casks for transport. Even when this method of acking' is adopted considerable loss will still occur during.transport, and also in pre aring the mixture of oxid and reducing coa, as the zinc oxid is very light and greatly inclined to become pulverulent. Another-defect is that during the reduction in the muffle, large lumps form from the loose 'oxid, and owing to the hcat'they coagulate and are then difficult to reduce, and owing to this coagulation the furnace ashes contam unreduced coagulated zinc oxld, and

this is another source of considerable loss of All defects can be obviated according to the present invention, in the following manner: The zinc oxid is treated in a mufile or reverberatory furnace, in which it is exposed for some considerable time, say two to three hours, to great heat, which may ad- Specification of Letters Patent.

Application filed March 29, 1909. Serial No. 486,573.

Patented Jan. 25, 11.910.

movcd from the settling chambers or dust flues. \Vhen the zinc oxid has been coagulated and solidified by heat in the manner described it is withdrawn from the mutlle or reverberatory furnace and allowed to cool. It can then he'transpwted in the same way as roasted blende and after the larger lumps have been broken up it can he used in the same manner as blende for forming the mixture for reduction to zinc. 'lho instability of zinc oxid, which is prejudicial in the reduction process, is entirely obviated by this means as is also the coagulation of the oxid in the mutlie during the reduction process.

Having described my invention what I claim and desire to secure by Letters Patent of the United States is Process of preparing zinc oxid for reduction and transport, consisting, in feeding zinc oxid. in the loose condition in which it is obtained from dust chambers or filtering apparatus, into a furnace, and subjecting said oxid, while retained in the furnace, to a ten'lperaturc of at least 1000 C. and until coagulated into dense, hard and heavy lumps mixed with hard granules. 4

In testin'lony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' HERMANN PAPE- Witnesses:

ERNEST H. L. MUMMENI-IOFF, IDA CI[RIST. I-lAr GRMANN. 

